1. Field of the Invention
The present invention relates to a novel polymer having a sulfonic acid ester group and a method for forming a relief, a printing plate or a photographic duplicate by using the polymer.
2. Description of the Prior Art
Heretofore, many studies have been made on the systems which undergo changes in solubility, adhesiveness, hardness or the like at the areas irradiated with light or electromagnetic waves, and some of them are being put into practice.
In the prior art, many studies have been made on light-sensitive compounds such as .alpha.,.beta.-unsaturated carboxylic acid derivatives and .alpha.,.beta.-unsaturated carbonyl compounds (for example, (1) J. Kosar, Light Sensitive Systems, John Wiley & Sons, New York, 1965, Chap. IV; (2) A. Schonberg, Preparative Organic Photochemistry, Springer-Verlag, New York, 1968, Chap. 8). In particular, the photoaddition four-membered ring-forming reaction of cinnamic acid derivatives has been studied extensively among the unsaturated carboxylic acids (for example, (3) P. Silber, Ber. dtsch. Chem. Ges., 35, 4128 (1902)) and, furthermore, the application of high molecular weight compounds having cinnamic acid ester groups to a light-sensitive system has also been well studied (for example, Silber, ibid., U.S. Pat. Nos. 2,835,656; 3,357,831; 3,737,319; 3,418,295; 3,647,470; 3,409,593; 2,956,878; 3,173,787; 3,023,100; 3,066,117; and 3,756,820 and British Pat. No. 695,197).
The inventor has previously developed an image-forming method utilizing, as the novel light-sensitive polymer compound not described in the above-described studies, a high molecular compound having .beta.-aryl-.alpha.,.beta.-unsaturated sulfonic acid ester groups or amido groups.
As a result of further investigations, the inventor has now discovered that sulfonic acid ester group containing polymers having no unsaturated bond at the .alpha.,.beta.-position also exhibit extremely good light-sensitivity, and thus developed the present invention.